1. Field of the Invention
This invention relates to a process for the conversion of a mixture of (1) methanol, dimethyl ether or mixtures thereof and (2) water to light olefins in the presence of a crystalline aluminosilicate zeolite of the erionite-offretite family.
2. Description of the Prior Art
U.S. Pat. No. 3,036,134 to Mattox discloses conversion of methanol to a reaction product containing water and dimethyl ether in the presence of a sodium or calcium crystalline aluminosilicate zeolite catalyst.
U.S. Pat. No. 3,529,033 to Frilette and Weisz discloses dehydration of a normal alkanol of three to six carbon atoms to an olefin, utilizing a sodium or calcium crystalline aluminosilicate zeolite catalyst having uniform interstitial dimensions sufficiently large to admit the alkanol charge and to permit egress therefrom of the olefin product.
The prior art, typified by the above patents, has, neither disclosed nor recognized the advantages of a process for selectively converting a mixture of (1) methanol, dimethyl ether or mixtures thereof and (2) water to C.sub.2 -C.sub.3 olefins utilizing the crystalline aluminosilicate zeolite catalyst described herein.
As those in the art are aware, a remarkable growth in the production of synthetic fibers, platics and rubber has taken place in recent decades. Their growth, to a very large extent, has been supported and encouraged by an expanding supply of inexpensive petroleum raw materials such as ethylene and propylene. Increasing demand for these light olefins has, from time to time, led to periods of shortage, either due to a diminished supply of suitable feedstocks or to limited processing capacity. In any event, it is considered highly desirable to provide efficient means for converting raw materials other than petroleum to light olefins.